<template>
  <div class="star" :class="starType">
    <span v-for="itemClass in itemClasses" :class="itemClass" class="star-item" track-by="$index"></span>
  </div>
</template>

<script type='text/ecmascript-6'>
  // 评分几颗星
  const LENGTH = 5;
  // 星星的状态
  const CLS_ON = 'on';
  const CLS_HALF = 'half';
  const CLS_OFF = 'off';

  export default {
    props: {
      size: { // 长度
        type: Number
      },
      score: { // 分数
        type: Number
      }
    },
    // 计算属性
    computed: {
      starType() {
        return 'star-' + this.size;
      },
      itemClasses() {
        let result = [];
        let score = Math.floor(this.score * 2) / 2;
        let hasDecimal = score % 1 !== 0;
        let integer = Math.floor(score);
        for (let i = 0; i < integer; i++) {
          result.push(CLS_ON);
        }
        if (hasDecimal) {
          result.push(CLS_HALF);
        }
        while (result.length < LENGTH) {
          result.push(CLS_OFF);
        }
        return result;
      }
    }
  };
</script>

<style lang='stylus' rel='stylesheet/stylus'>
  @import "../../common/stylus/minxin.styl"
  .star
    font-size :0
    .star-item
      display :inline-block
      background-repeat :no-repeat
    &.star-48
      .star-item
        width: 20px
        height: 20px
        margin-right :22px
        background-size :20px 20px
        &:last-child
          margin-right :0
        &.on
          bg-image('star48_on')
        &.half
          bg-image('star48_half')
        &.off
          bg-image('star48_off')
    &.star-36
      .star-item
        width: 15px
        height: 15px
        margin-right :16px
        background-size :15px 15px
        &:last-child
          margin-right :0
        &.on
          bg-image('star36_on')
        &.half
          bg-image('star36_half')
        &.off
          bg-image('star36_off')
    &.star-24
      .star-item
        width: 10px
        height: 10px
        margin-right :3px
        background-size :10px 10px
        &:last-child
          margin-right :0
        &.on
          bg-image('star24_on')
        &.half
          bg-image('star24_half')
        &.off
          bg-image('star24_off')

</style>
